Diy fmic
 

Looking at the intake pipe running under the bumper in front of the engine, and the astronomical (including corresponding mark-up) price of the offered FMIC kits ($1,000 for an intercooler, 4 bent pipes, 8 flex connectors and a bunch of hose clamps), I am wondering:

Just take this pipe out (hose clamp on passenger and driver side), cut and splice a small intercooler in IN ADDITION to the factory intercooler?

Cost: $100 plus some elbow grease.

A full DIY with replacing the factory IC requires some custom tube bending and fit fiddling.

I'm sure no-one has done that, but looking for comments:

- flow: will the larger internal cross section of the intercooler (compared to a straigt pipe (my guess: the insided diamter of the current pipe is 1.75 inch?) add further flow restrictions?

- intercooler area: well, obvious at least twice as much

- 'heat sink': the additional thermal mass will act as an additional heat sink, which IMO can be good an bad: it can quickly take out heat for short periods of high boost (= high temperature), but will also give back heat for no boost periods.

Your thoughts?

I think it will create a noticeable pressure drop and extra lag because of the added volume and 2 IC cores... i also think its overall just a dumb idea no offense lol. Your k03 wont like it, and according to your sig you are only running 12.5psi which is pretty low for a chipped 1.8t. scrap the idea and buy an ebay fmic kit.

What is the recommended (no more than 300 hp peak)
- intercooler size
- connecting pipe diameter

(obviously: compromise between "bigger the better" = increased lag and larger heat sink mass, but lower flow restriction vs. "smaller is better" = less lag, less heat sink, higher flow restrictions).

I remember seeing somewhere that 2" is good, 2.25" is plenty and everything above just adds lag?

one of the small ebay cores with like 2" piping is more than enough for a k04. But if you plan on going BT in the future then i would just spend the money on a real (big) fmic.

Anyone know what the OEM sizes/dimension are for
- the intercooler
- the connecting pipes

The intercooler pipes are 2 inch. Don't do that set up. I did my FMIC for 120 (ebay and craigslist baby!). Look in the DIY section for FMIC write up...

I used the DIY FMIC write up as a decision tool to
- not attempt to do the bends from scratch
- use ebay 'custom' kit for 300 incl 20x6x2.75 plus 2" pipe

I I had to do it again, I would only change the thickness of the IC from 2.75 to 2.5.

In this post are photos and links.

https://www.audiforums.com/forum/sho...d.php?t=147018